Riding bicycles is a popular way to get exercise. Bicycles are typically human powered and have two wheels connected by a frame. The rear wheel is typically geared to a crank shaft with pedals. To propel the bicycle, the user can rotate the pedals of the crank shaft with his or her feet.
Some bicycles incorporate a motor that is arranged on the bicycle to rotate the wheels. Often, such a motor is intended to assist the user in propelling the bicycle. In other words, the user may still pedal with such a bicycle, but the motor can make the pedaling easier. In some situations, the user can stop pedaling altogether and rely solely on the motor to propel the bicycle forward.
One type of electric powered vehicle is disclosed in U.S. Pat. No. 6,446,745 issued to Michael John Lee, et al. In this reference, a control system for an electric powered vehicle provides substantially greater control and related features than the simple control systems known in the art. The control system can be utilized with any type of electric powered vehicle, such as bicycles, scooters, tricycles, four-wheeled vehicles and the like. In a first embodiment of the invention, the control system estimates an amount of heat generated in the vehicle electric motor and assigns heat credits based on the relationship between the estimated motor heat and a predetermined heat level. The operation of the motor is then controlled in accordance with the available heat credits so as to prevent overheating of the motor. In a second embodiment of the invention, the control system monitors the current state of charge of the battery and presents that information to the rider. Since the battery voltage is affected by the load on the battery mostly due to the motor, the motor is periodically disconnected from the battery so that an unloaded battery voltage measurement can be made. In a third embodiment of the invention, the control system monitors the current operational state of the motor to detect a failure mode in which the full battery voltage is applied to the motor, potentially causing it to run away at full torque and full speed. When a failure mode is detected, the control system first attempts to shut off control signals to the motor. If this fails to stop the failure mode condition, the control system disconnects the battery from the motor by opening a fuse. In a fourth embodiment of the invention, the control system includes a cruise control feature that allows the electric powered vehicle to operate at a desired speed set by the rider. In a fifth embodiment of the invention, the control system controls operation of vehicle lights to accommodate variations in battery voltage. In a sixth embodiment of the invention, the control system controls operation of a horn so that it can also function to provide audible signals reflection operational conditions of the vehicle. In a seventh embodiment of the invention, the control system allows the vehicle to operate in a biofeedback mode to serve as an exercise or training device for the rider. Another type of systems is described in U.S. Patent Publication No. 2009/0181826 issued to James R. Turner, et al and European Patent Application No. EP2657865A1 issued to Iwan Van Hende. All of these documents are herein incorporated by reference for all that they contain.